Apparatus and method to provide a single reference component for multiple circuit compensation using digital impedance code shifting

摘要

A single external impedance element is used to perform multiple circuit compensation. A reference impedance code is first generated based on matching an internal impedance generated by transistors with an impedance of the external impedance element, and then the reference impedance code can be shifted to generate new impedance codes according to impedance requirements of various different circuits that require compensation. Use of the single external impedance element for compensation of multiple circuits reduces motherboard and packaging costs. Chip area is also conserved since simpler compensation circuits can be used.